CHOLINERGIC AGENTS 2025
Adrenergic Agonists
Overview of Adrenergic Agonists
• Adrenergic agonists activate the sympathetic nervous
system (SNS) by stimulating adrenergic receptors,
leading to various physiological responses.
• Epinephrine is a primary example, increasing blood
pressure (BP) via alpha-1 receptors, heart rate (HR)
via beta-1 receptors, and promoting bronchodilation
via beta-2 receptors.
• These agents are crucial in emergency medicine,
particularly in treating anaphylaxis and cardiac arrest.
Mechanism of Action
• Activation of alpha-1 receptors causes
vasoconstriction, increasing BP and reducing GI
motility.
• Beta-1 receptor activation increases heart rate and
myocardial contractility, enhancing cardiac output.
• Beta-2 receptor activation leads to bronchodilation,
facilitating easier breathing during asthma attacks.
,Indications for Use
• Commonly used in asthma and bronchospasm
management, providing rapid bronchodilation.
• Essential in treating severe allergic reactions
(anaphylaxis) and cardiac arrest situations.
• Also indicated for nasal congestion relief due to its
vasoconstrictive properties.
Side Effects and Adverse Reactions
• Side effects include anorexia, nausea, restlessness,
insomnia, and hyperglycemia.
• Adverse reactions can be severe, including
palpitations, tachycardia, and potential ventricular
fibrillation.
• Monitoring is crucial, especially in patients with pre-
existing conditions.
Nursing Interventions
• Vital signs should be monitored before and after
administration to assess the drug's effects.
• Blood glucose levels must be checked due to the risk
of hyperglycemia.
, • Close monitoring of patients with cardiac disease,
diabetes, and pregnant women is essential.
Adrenergic Antagonists
Overview of Adrenergic Antagonists
• Adrenergic antagonists block alpha and beta
receptors, counteracting the effects of adrenergic
agonists.
• Commonly used to manage hypertension and other
cardiovascular conditions.
Types of Adrenergic Antagonists
• Alpha-1 blockers (e.g., Prazosin) primarily affect
blood vessels, leading to vasodilation and reduced
BP.
• Beta-1 blockers (e.g., Atenolol) primarily affect the
heart, decreasing heart rate and myocardial
contractility.
Indications for Use
• Indicated for hypertension, angina, heart failure, and
certain dysrhythmias.
• Beta blockers are also used to prevent migraines and
manage anxiety.